If it's the stock quadrant and you're looking to replace it with an aftermarket, then you'll need to replace the quadrant and install a firewall adjuster.
You other option (of course) would to be to replace the quadrant and prawl with a new (or used) OEM piece.
When I did mine, I spent approx 2 hours to do the swap. Its not bad so long as you go into the project knowing that you're going to have the patience to look at it all thoroughly and take your time disassembling the old stuff and putting on the new stuff. Getting frustrated because of the tight spaces makes the job suck.
I used the Maximum Motorsports OEM cable, quadrant, and firewall adjuster. They work great, no complaints. The quadrant is damned near stock in action and doesn't make for a hard to push pedal like many of the quick release quadrants do. I posted this the other day but had I to do it over again, I would have put a Fiore Micro-Click firewall adjuster in as opposed to the MM piece. It has no friction ring (making it easier to turn) and also has a nice knurled grip for grabbing onto to make adjustment. The ball bearing locking feature ensures it stays where you put it. My adjuster is a little difficult to get to because of where my blower sits. Having the Fiore I think, would just have made it easier for me to adjust when I'm only able to get 2 fingers on it. The MM adjuster is still a nice piece and works well though.